The present invention relates to an electrophotographic copying machine and, more particularly, to a hinge structure using a torsion bar of an electrophotographic copying machine in which a hinge can be stressed by the torsion moment of the torsion bar toward a predetermined direction to fascilitate the opening and closing of an object connected with the hinge.
A type of electrophotographic copying machine is proposed which includes a housing separated into an upper body and a lower body as disclosed, for example, in Itoh et al U.S. Pat. No. 4,416,536, issued on Nov. 22, 1983, entitled LIGHT MEMORY REMOVING SYSTEM IN AN ELECTROPHOTOGRAPHIC COPYING MACHINE. A stable and suitable hinge structure for such a type of copying machine has not yet been proposed.